GEOLOGICAL SUEVEY OF THE TEEEITOEIES. 365 



LojpMotherium Ballardi. 



A second and smaller species, named by Prof. Marsh, from a jaw 

 fragment witli teeth, found at Grizzly Buttes, Wyoming. The last 

 lower molar tooth measures scarcely 4J lines fore and aft, whereas in the 

 former species it measures 5^ lines. 



Titan OTHEEIUM. (?) 



Titanoilierium (?) anceps. 



Some remains of the largest mammal of the Bridger Tertiary forma- 

 tion have been referred with doubt by Prof. Marsh to the genus 

 TitanotJierium. The animal was about two-thirds the size of the Titano- 

 therium Proioti, of the Mauvaises terres of White Eiver, Dakota. Per- 

 haps the remains I have referred to Palceosyops major may belong to the 

 same. 



EVEN-TOED PAOHYDEEMS. 

 Elothbeium. 



Elotlierium lentis. 



A species of suilline pachyderms, indicated by Prof. 'Marsh and 

 founded on a jaw fragment containing a last molar tooth, from Henry's 

 Fork of Green Eiver, Wyoming. The si^ecies was about half that of 

 Elotlierium Mortoni of the Mauvaises terres of White Eiver, Dakota. 



Platygonus. 



Platygonus Ziegleri. 



Another suilline pachyderm, indicated by Prof. Marsh, he refers 

 to the Peccary-like genus above named. It is founded on specimens 

 obtained at Grizzly Buttes, Wyoming. The species was as large as the 

 Domestic Hog. 



BIEDS. 



Of remains of birds I have detected no trace of bones, among the col- 

 lections of fossils, from the Tertiary formation of Wyoming, Avhich have 

 been submitted to my inspection. 



Prof. Hayden exhibited to the writer an interesting specimen, con- 

 sisting of the impression of the distal extremity of a feather in a 

 fragment of shale, which was discovered among the Green Eiver shales, 

 so remarkable for the great number of well-preserved fishes they con- 

 tain. 



Bubo. 



Bubo leptosteus. 



Prof. Marsh, who has taken especial pains to seek for those rarest 

 of fossils, the remains of birds, reports the discovery of some bones in 

 the Tertiary beds of the Green Eiver Basin. One of these, from Grizzly 

 Buttes, he refers to an owl about two-thirds the size of the Great-Horned 

 Owl. The species is named as above. 



